| # Copyright 2009 the Melange authors. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| """The module which contains functions to manage tags in Melange. |
| """ |
| |
| |
| class TagsService(object): |
| """Helper class for tags corresponding to a model. |
| """ |
| |
| def __init__(self, tag_names): |
| """Defines tag names. |
| """ |
| |
| self.tag_names = tag_names |
| |
| def prepareTagsForStoring(self, fields, scope): |
| """For those fields which represent task values it prepares actual |
| tag entries. |
| |
| Args: |
| fields: a dict mapping tag names with values |
| scope: scope for the tag that will be stored |
| """ |
| |
| for tag_name, tag_value in fields.iteritems(): |
| if tag_name in self.tag_names: |
| fields[tag_name] = {'tags': tag_value, 'scope': scope} |
| |
| def setTagValuesForEntity(self, entity, fields): |
| """Sets tag values for a particular entity based on fields dictionary. |
| |
| Args: |
| entity: an entity which is to be tagged |
| fields: a dict mapping tag names with values |
| """ |
| |
| if not entity: |
| return None |
| |
| for tag_name, tag_value in fields.iteritems(): |
| if tag_name in self.tag_names: |
| setattr(entity, tag_name, tag_value) |
| |
| return entity |
| |
| def removeAllTagsForEntity(self, entity): |
| """Removes all tags defined for a particular entity. |
| |
| Args: |
| entity: entity which the tags will be removed for |
| """ |
| |
| self.removeTagsForEntity(entity, self.tag_names) |
| |
| def removeTagsForEntity(self, entity, tag_names): |
| """Removes all tags values for a particular entity based on tag_names |
| list with name of the tags that are to be removed. |
| |
| Args: |
| entity: entity which the tags will be removed for |
| tag_names: list of tags to remove |
| """ |
| |
| if not entity: |
| return |
| |
| for tag_name in tag_names: |
| if tag_name in self.tag_names: |
| cls = entity.tags_class(tag_name) |
| tags = cls.get_tags_for_key(entity.key()) |
| for tag in tags: |
| tag.remove_tagged(entity.key()) |
| |
| |
| def getTagsForProgram(model, program, order=None, limit=1000): |
| """Fetches all the tag entities for the given program. |
| |
| Args: |
| model: The tag model class for which the tags must be fetched |
| program: The program entity for which the tags must be fetched |
| order: A list of model properties on which the query should be ordered |
| limit: number of entities that must be fetched |
| """ |
| q = model.all() |
| q.filter('scope', program) |
| if order: |
| for o in order: |
| q.order(o) |
| |
| return q.fetch(1000) |